Virtual Extensible LAN (VXLAN) is a network virtualization technology that attempts to ameliorate the scalability problems associated with large cloud computing deployments. It uses a VLAN-like encapsulation technique to encapsulate MAC-based OSI layer 2 Ethernet frames within layer 4 UDP packets, using 4789 as the default IANA-assigned destination UDP port number. VXLAN is an evolution of efforts to standardize on an overlay encapsulation protocol. It increases scalability up to 16 million logical networks and allows for layer 2 adjacency across IP networks. Multicast or unicast with HER (Head-End Replication) is used to flood BUM (broadcast, unknown destination address, multicast) traffic.